The state of ABF substrates in data center silicon in 2026 — solving the supply crunch and material wall beneath every AI accelerator

(Image credit: Getty Images / Richard A. Brooks) ABF substrates, the specialized insulating and wiring bases that connect tiny silicon chips above them to the much larger printed circuit boards below, sit beneath most high-end CPUs, GPUs, and AI accelerators. Featuring the Ajinomoto build-up film (ABF), these substrates have been critical to the semiconductor industry since the late 1990s, with personal computers, workstations, servers, and networking silicon driving steady demand for decades.The artificial intelligence boom has multiplied that demand exponentially. Training and inference for frontier models now run across data centers, each housing hundreds of thousands of accelerators and providing hundreds of megawatts of compute. Nvidia alone shipped an estimated 3.2 million Blackwell GPU packages through the end of 2025, with every one of those accelerators packaged on an ABF substrate. Meanwhile, the industry is already entering the gigawatt era with humongous data center buildouts, each expected to house millions of AI accelerators. Etiido Uko is a news contributor for Tom's Hardware covering the latest updates in big tech and the PC industry. He is a mechanical engineer and senior technical writer with over nine years of experience in documentation and reporting. He is deeply passionate about all things engineering and technology, and is an expert in gadgets, manufacturing, robotics, automotive, and aerospace.